This invention pertains to the art of video inspection or detection, and more particularly to such systems employed in parcel or package sorting mechanisms.
The invention is particularly applicable to detection of multiple, adjacent parcels such as a stream of envelopes for bulk mail sorting and will be described with particular reference thereto. However, it will also be appreciated that the invention has broader application, such as in the detection of a number of adjacent, sheet-like units in any fabrication or sorting application.
Presently, a relatively large market exists for bulk sorting of mail parcels. Such sorting may be utilized to accommodate mass mailings, particularly to allow for lower mailing rates associated with pre-sorted packages. Typically, a sorting operation includes a conveyor which communicates the parcels, such as envelopes, in a stream for imprinting of indicia, as well as for optical character recognition of address information thereon. One problem with such sorting occurs when two parcels are disposed adjacent, or partially adjacent, to one another on the conveyor. This may result in the obliteration or corruption of address information during an OCR reading, or masking of an envelope during a printing operation. This may, in turn, result in missed addressing or improper addressing or routing.
Several system have been employed in the past to attempt to detect such overlapping parcels. Such systems include thickness gauges of the mechanical or optical variety, as well as systems gauging density changes. While such systems have utility when limited to sorting parcels which are all of the same general size or type, they suffer or are ineffective in the event mixed parcels are present. Density sensing systems are particularly deficient in discriminating between thick parcels and a plurality of thin ones.
While sorting is utilized in connection with pre-mailing operations, it is also utilized in connection with processing address information for the recipient, such as occurs at a post office upon mailing. Detection of multiple, adjacent items at this level is even more difficult due to the myriad of parcel sizes which must be processed and sorted. The same problem is to be expected during pre-mailing sorting as bulk pre-sorting is utilized for general mailings, other than mass mailings of a single parcel type.
Postal regulations and economics are moving to mandate more and more pre-sorting, particularly in business mailing. Often times business mailings result in multiple, non-uniform parcels.
Accordingly, there is a demand for a reliable detection means for determining the presence of multiple, adjacent parcels traveling along a stream thereof. Further, there is a demand for a system which accomplishes detection of such multiple units when confronted with parcels of varying or various sizes.
The present invention contemplates a new and improved parcel detection system which addresses the above-referred problems, and others, and provides a detection system which reliably ascertains the presence of adjacent or overlapping parcels in a stream which is not adversely affected by lack of uniformity between the parcels, and is able to work at a high parcel flow rate.